Help me im woried! can dry sex get me pregnat even with pants on?

well last week me and my boyfriend had dry sex, I had pants and my undies and he had his boxers and shorts,wen i went back home i saw that my pants were all went by my vagina, I think thats my cum, is there a way it can be his sperm too?Im woried because my aut told me that she dreamed that i was pregnate and you know i want to make sure that non of his sperm got in me.Can i get pregnate if he cums in my vaginal lips even if im still a vergin? PLEASE HEL ME IM WORIED! Tweet